Functional Performance Evaluation of NU-FlexSIV Socket

The proposed clinical trial will be an assessor-blinded prospective randomized cross-over
trial wherein participants with unilateral transfemoral amputation will be randomized to
using one of two socket conditions (i.e., sub-ischial or ischial containment) before crossing
over to the other socket condition. Random allocation (computer-generated) utilizing blocks
of random size will be used to assign the initial treatment condition. The trial will be
balanced such that all subjects will receive all treatments (i.e., both socket conditions)
and that all subjects will participate for the same number of periods (i.e., two). While a
washout period is not strictly necessary, it is effectively included as subjects will need to
transition back to their usual, pre-study socket/prosthesis while the second test socket is
fabricated.

Allocation of intervention will be concealed from the investigators until after a subject is
enrolled. The starting socket design will be enclosed in sequentially numbered, opaque,
sealed envelopes. Envelopes will be opened sequentially and only after the participant's name
and other details are written on the appropriate envelope.

Blinding of prosthetic interventions is challenging given that they are devices that must be
custom-fabricated and donned each day by the subject. Hence, for this study only the assessor
will be blinded. The blinded assessor will be responsible for administration of the clinical
performance and patient-reported measures as well as processing of motion analysis data.

Inclusion Criteria:

- unilateral transfemoral amputation

- have used a prosthesis for two or more years

- have a residual limb that is stable in volume and free from wounds

- be physically fit enough to participate in the performance tests (Medicare Functional
Classification Level K3 or K4)

- have no previous experience of the sub-ischial socket

- able to complete all visits for the duration of the protocol

Exclusion Criteria:

- have a residual limb femur of less than 5-inches

- co-morbidities that affect function, including neurologic abnormalities (e.g.
neuropathic pain that would interfere with the study)

- do not speak and read English